CVE-2021-4207
A flaw was found in the QXL display device emulation in QEMU. A double fetch of guest controlled values `cursor->header.width` and…
- Published
- Updated
- Reserved
- Assigned by
- redhat
Description
A flaw was found in the QXL display device emulation in QEMU. A double fetch of guest controlled values `cursor->header.width` and `cursor->header.height` can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. A malicious privileged guest user could use this flaw to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.
Timeline
ID reserved
By redhat
- 4 months later
· 4 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | High8.2 | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.40% · top 65% of all CVEs (7 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.2.
Weakness
Affected products
QEMU
- affected qemu-kvm 7.0.0
References (6)
- https://bugzilla.redhat.com/show_bug.cgi?id=2036966 (opens in a new tab)x_refsource_MISCx_transferred
- https://starlabs.sg/advisories/21-4207/ (opens in a new tab)x_refsource_MISCx_transferred
- DSA-5133 (opens in a new tab)vendor-advisoryx_refsource_DEBIANx_transferred
- GLSA-202208-27 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
- [debian-lts-announce] 20220905 [SECURITY] [DLA 3099-1] qemu security update (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- https://security.netapp.com/advisory/ntap-20250321-0009/ (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2021-4207)Record last updated .